The present invention relates to a valve or pump gasket for sealing a fluid dispenser device comprising a valve or a pump mounted on a fluid container.
More particularly, the gaskets of the invention are suitable for being used both in dispenser devices for dispensing pressurized fluid and including valves, and in particular metering valves, and also in dispenser devices for dispensing non-pressurized fluid and including pumps.
The gaskets used in pressurized fluid dispensers, such as aerosol devices must satisfy certain conditions and requirements. Thus, such gaskets must offer good mechanical properties, and good resistance to moisture, and must not swell too much when in contact with the propellants. In particular, such characteristics are especially important for dynamic gaskets that provide sealing between the moving valve member of the valve and the valve chamber that contains the metered quantity to be expelled.
For various reasons, and in particular for ecological reasons, chlorofluorocarbon (CFC) type propellants have largely been replaced by hydrofluoro-carbon (HFC) propellants of the HFC-134a or HFC-227 types, with or without alcohol. The use of such propellants, in particular when they are used with about 20% by weight of ethanol being added, increases the stresses on the gaskets, so that the conventional materials that were used in association with CFC gases no longer present optimum characteristics.
In addition, the gaskets used in non-pressurized fluid dispenser devices, and in particular pumps, must also satisfy certain conditions and requirements. Thus, such gaskets must offer good resistance to solutions, in particular to water and ethanol solutions, i.e. solutions containing water, ethanol, or a mixture of water and of ethanol. Furthermore, such gaskets must offer good resistance to moisture and good resistance to preservative agents, such as quaternary ammonium compounds.
An object of the present invention is to provide valve or pump gaskets that satisfy the above-mentioned requirements.
An object of the present invention is to provide a valve gasket that is designed to come into contact with a fluid and with a propellant of the hydrofluoroalkane (HFA) type, with or without alcohol, and that guarantees good mechanical properties and/or low swelling and/or good resistance to moisture.
Another object of the present invention is to provide a pump gasket that offers good resistance to water/ethanol solutions and/or good resistance to moisture, and/or good resistance to preservative agents, such as quaternary ammonium compounds.
Yet another object of the present invention is to provide a valve or pump gasket that is simple and inexpensive to manufacture.